Fig 5. A robotic sperm achieves helical flagellar propulsion under the influence of out-of-plane magnetic field that follows a cone pointing in the direction of motion.

The robot swims at an average speed of 38.1±0.6 μm/s in silicone oil with viscosity 1 Pa.s, at frequency of 1 Hz (S3 Dataset). The red curve indicates the real shape of the robot, whereas the blue curve is superimposed to represent the propagating wave along the flexible tail (S3 Video).